Croatian Digital Thesis Repository
Not a member yet
259189 research outputs found
Sort by
Domestication and breed development of domestic cat
No full textDomaća mačka, Felis silvestris catus, pripitomljena je na Bliskom istoku kada su
ljudi počeli graditi trajna naselja. Brojni su dokazi odnosa ljudi i različitih vrsta mačaka
tijekom prošlosti, ali samo je europska divlja mačka, Felis silvestris silvestris pripitomljena,
te je ona predak današnje domaće mačke, Felis silvestris catus. Tek se u 19. stoljeću mačke
počinju uzgajati zbog njihove ljepote, a ne samo zbog njihove koristi u lovu na štetočine, što
je ujedno bio i glavni razlog pripitomljavanja. Na prvoj izložbi mačaka 1871. godine
predstavljene su neke od najstarijih pasmina kao što su perzijske, sijamske i manks mačke,
a nakon izložbe povećao se uzgoj novih pasmina te je danas u svijetu priznato preko 50
pasmina mačaka.The domestic cat, Felis silvestris catus, was domesticated in the Middle East
when humans began building permanent settlements. There are many evidence of
relationships between humans and different cat species over the past, but only the European
wild cat, Felis silvestris silvestris, has been domesticated and it is the ancestor of the presentday domestic cat, Felis silvestris catus. It was not until the 19th century that people began
to breed cats for their beauty, not just for their benefits in pest hunting, which was also the
main reason for domestication. The first cat show in 1871 featured some of the oldest cat
breeds such as Persian, Siamese and Manx. After the show number of new breeds increased,
and today over 50 cat breeds are recognized worldwide
EFFECT OF PESTICIDES ON SOIL MICROBIOM
No full textŠirenjem poljoprivredne industrije počinje onečišćavanje tla, vode i zraka što zahtijeva
primjenu pesticida. Iako su pesticidi uvelike pomogli očuvati usjeve od raznih štetočina i patogena, ljudi nisu
bili svjesni posljedica koje dolaze nakon primjene agresivnih kemikalija. Aktivne tvari pesticida šire se kroz
ekosustave te negativno utječu na sveukupnu floru i faunu, uključujući i mikrofloru tla. Mikroorganizmi u tlu
ključni su za održavanju kvalitete tla, biljaka, hrane i kruženje kemijskih elemenata koji određuju plodnost i
kvalitetu tla. Najveći problem primjene pesticida je njihov uglavnom negativan utjecaj na ne-ciljne organizme.
U ovom radu detaljnije je prikazana uloga mikroorganizama u tlu te posljedice primjene pesticida na različite
skupine mikroba.With the development of the agricultural industry, soil, water and air pollution are beccoming
more apperent. Although pesticides have greatly helped to preserve crops from a variety of pests and pathogens,
people were unaware of the consequences that are related to apllying aggresive chemicals. The active
substances of pesticides spread through ecosystems and negatively affects the overral flora and fauna, including
soil microflora. Soil microorganism are crucial for maintaining the quality of soil, plants, food, and the
circulation of chemical elements that determine soil fertility and quality. The biggest problem of pest
application is their mainly negative impact on non-target organisms. This paper presents in more detail the role
of microorganisms in the soil and the consequences of pesticide application on different groups of microbes
Alternative toxicology tests on chicken embryos
No full textPostoje brojna toksikološka istraživanja koja se provode na životinjama in vivo. Zbog etičkih i drugih
problema razvijaju se alternativni toksikološki testovai kao npr. in ovo na ptičjim jajima koji bi uklonili ove
dileme. Razvojem kulture pilećih embrija izvan ljuske moguće je osuvremenjivanje in ovo istraživanja
zahvaljujući direktnom promatranju promjena koje se događaju tijekom embrionalnog razvoja ptica.
U ovom radu se istraživala metoda simulacije ljuske jajeta kao osnove za provođenje toksikoloških testova na
embrijima jajeta. Pri tome su se istraživale promjene uvjeta pri provođenju eksperimenta na duljinu
preživljavanja embrija, kao što je npr. postotak vlage u zraku.There are numerous toxicological studies performed on animals in vivo. Due to ethical and other problems
alternative toxicological tests are being developed, such as in ovo on bird eggs which would eliminate these
dilemmas. With the development of a chick embryo culture outside the shell, it is possible to modernize in
ovo research by direct observation of the changes that occur during the embryonic development of birds.
In this thesis, the method of egg shell simulation as a basis for conducting toxicological tests on egg embryos
was investigated. In doing so, changes in conditions during the experiment on the length of embryo survival,
such as the percentage of humidity in the air were researched
Computational aerodynamic model of buildings with porous double-skin façades
No full textSustav dvostrukog pročelja se koristi s ciljem poboljšanja energetske učinkovitosti zgrade. Sustav se sastoji od unutarnjeg pročelja na koje je smješteno vanjsko pročelje, pri čemu razmak između dvaju pročelja može iznositi od nekoliko centimetara do dva metra. Posebnu vrstu sustava dvostrukog pročelja predstavlja sustav dvostrukog poroznog pročelja kod kojeg se poroznost postiže otvorima na vanjskom pročelju. Pri strujanju vjetra oko zgrade s dvostrukim poroznim pročeljem dolazi do strujanja zraka kroz otvore na vanjskom pročelju i između dvaju pročelja. Takvo strujanje uzrokuje raspodjelu tlaka na zgradi koja nije karakteristična za zgrade s jednostrukim pročeljem.
U ovom radu je provedena računalna analiza atmosferskog strujanja zraka oko modela zgrade s dvostrukim poroznim pročeljem za slučaj visoke poroznosti vanjskog pročelja. Modeli zgrade i poroznog pročelja, te značajke modela atmosferskog graničnog sloja, su preuzeti iz laboratorijskih mjerenja u zračnom tunelu. Ispitana su dva pristupa računalnom modeliranju strujanja vjetra. Prvi pristup je utemeljen na zadavanju volumenskog protoka fluida na ulazu u računalnu domenu, dok se drugi pristup temeljio na izravnom modeliranju strujanja homogenog atmosferskog graničnog sloja. Računalni model je razvijen u programskom paketu OpenFOAM, a prostorna diskretizacija računalne domene je izrađena pomoću programskog paketa CF-MESH+. Postignuti rezultati su uspoređeni s rezultatima laboratorijskih mjerenja.Double-skin façade systems have been commonly used to improve the energy efficiency of buildings. This type of façade systems consists of an internal façade onto which an external façade is placed, with the gap between the two façades ranging from a few centimeters to two meters. A special type of a double-skin façade system is the porous double-skin façade, where porosity is achieved using openings on the external façade. When the wind flows around buildings with this type of façade, air flow occurs through the openings on the external façade and between the two façades. This type of flow yields pressure distribution on the building that is not characteristic of buildings with a single façade.
In this study, the computational analysis of atmospheric air flows around the building model equipped with a porous double-skin façade was conducted for the case of high porosity of the external façade. The appearance of the building model and the porous façade, as well as the characteristics of the atmospheric boundary layer model, were adopted from the wind-tunnel experiments. Two approaches to computational modeling of the wind flow were addressed. The first approach involved specifying the volumetric flow of the fluid at the inlet to the computational domain, while the second approach was based on the direct modeling of the homogeneous atmospheric boundary layer. The computational model was developed using the OpenFOAM software package, while the spatial discretization of the computational domain was performed using the CF-MESH+ software package. The obtained results were compared with the results of laboratory experiments
Symmetric functionalization of Anderson-type polyoxomolybdates
No full textIstražene su mogućnosti funkcionalizacije Andersonovog heteropolioksomolibdata s organskim i metaoloorganskim spojevima. Sintetiziran je simetrično funkconalizirani spoj [N(C4 H9 )4] 3[CoMo6 O18{(OCH2 )3CNH2 }2], a potom njegovom reakcijom s hidrazonskim kompleksom bakra [Cu3 (μ 3 -NO3){(C5 H4N)CH=N–N(C=O)(C5 H4 N)}3 (H2 O)3 ]n(NO3 )2n·3nH2O dobiven je hibrid složene strukture. Koordinacijom aminskih skupina funkcionaliziranog polioksometalata na atome bakra, polianion povezuje dva periferna koordinacijska polimera u jedinstvenu strukturu. Analognom reakcijom s [Cu(NO3 ){(C5 H4 N)2CH=N–NH(C=O)(C5 H4 N)}]2 (NO3 )2 nije bilo moguće prirediti hibrid sličnog sastava. Sljedeći pristup temeljen na reakciji [Cu2(OAc)4 (3-pyCHO)2] s [N(C4 H9 )4]3[CoMo6 O18{(OCH2 )3CNH2 }2] nije doveo do povezivanja dvaju podjedinica već do nastajanja imina. Direktnom reakcijom [N(C4 H9 )4] 3[CoMo6 O18{(OCH2 )3CNH2 }2] s 4-piridinkarbaldehidom priređen je heteropolioksometalat [N(C4 H9 )4]3[CoMo6 O18{(OCH2 )3C=NCHC5 H4 N}2].The functionalization of Anderson-type heteropolyoxomolybdate with organic and metalorganic compounds was investigated. Symmetrically functionalized compound [N(C4 H9 )4] 3[CoMo6 O18{(OCH2 )3CNH2 }2] was prepared, and afterwards, by its reaction with copper hydrazone [Cu3 (μ 3 -NO3){(C5 H4N)CH=N–N(C=O)(C5 H4 N)}3 (H2 O)3 ]n(NO3 )2n·3nH2 O complex, a hybrid with a complex structure was obtained. The polyanion connects the two peripheral coordination polymers into a unique structure by coordinating the amine groups of the functionalized polyoxometalate to the copper atoms. By analogous reaction with [Cu(NO3 ){(C5 H4 N)2CH=N–NH(C=O)(C5 H4 N)}] 2 (NO3 )2, it was not possible to prepare a hybrid with a similar composition. The next approach was based on the reaction of [Cu2(OAc)4 (3-pyCHO)2] with [N(C4 H9 )4] 3[CoMo6 O18{(OCH2 )3CNH2 }2], but this method did not result with the interconnection of the two subunits, but instead the imine formed. The heteropolyoxometalate [N(C4 H9 )4]3[CoMo6 O18{(OCH2 )3C=NCHC5 H4 N}2] was prepared by direct reaction of [N(C4 H9 )4] 3[CoMo6 O18{(OCH2 )3CNH2 }2] with 4-pyridinecarbaldehyde
Review and analysis of stone processing production line
No full textKroz rad objašnjeni su osnovni teorijski pojmovi potrebni za razumijevanje napisanog, kao što su proizvodni i tehnološki proces, efektivnost, efikasnost, produktivnost te je dan uvid u kamen kao materijal. Opisano je poduzeće Gorica kamen d.o.o., djelatnost, proizvodni program, proizvod, tehnološki proces izrade, plan proizvodnje te elementi unutar iste (strojevi, alati i ostala oprema). Prikazani su podaci o izradi pojedinih proizvoda u nekoliko etapa. Sastavljen je dijagram toka od narudžbe kupca do montaže gotovog proizvoda. Objašnjena su vremena proizvodnje i gubici te su predložena moguća poboljšanja.Through the paper, the basic theoretical contepts necessery for understanding what is written are explained, such as the production and technological process, effectiveness, efficienci, productivity and the insight into the stone as material. The company Gorica kamen d.o.o., it's activity, production program, product, manufacturing process, prodaction plan and elements within it (machines, tools and othe equipment) are described. Data on the production of individual product in several stages are presented. A flow chart was drawn up from the customer's order to the assembly of the finished product. Production times are explained and possible improvements are suggested
Design of battery pack mounting bracket as part of prototype battery-driven electric train development
No full textTema ovog završnog rada je konstruiranje i simuliranje nosača krovnih baterija vlaka putem programskog paketa CATIA na način da zadovolje normu HRN EN 12633. Nosače je potrebno izraditi iz legure AlZn10Si8Mg postupkom gravitacijskog lijevanja u pješčani kalup. Prije konstruiranja objašnjena je navedena norma, postupak lijevanja i razlog korištenja navojnih umetaka za vijčane spojeve. Zatim rad prikazuje iterativni postupak dolaska do konačnog proizvoda simuliranjem inačica nosača jednu za drugom unaprjeđujući ih sve do zadnje. Nakon dobivenog oblika konačnog nosača proizveden je 3D printani model koji služi za proizvodnju pješčanih kalupa. Korištenjem programskog paketa Altair Inspire Cast simulirano je lijevanje aluminijske legure u kalup i naznačeni potencijalni problemi prilikom lijevanja te je prikazan postupak lijevanja uživo. Na kraju rada nalaze se rezultati ispitivanja provedenih tokom proizvodnje nosača kako bi se usporedio nosač dobiven u programskom paketu sa stvarnim rezultatima ispitivanja.The subject of this final paper is the construction and simulation of train roof battery supports using the CATIA software package in such a way that the HRN 12633 standard is met. The supports must be made from the AlZn10SiMg alloy using gravity die casting into a sand mold. Before constructing, the stated norm, casting process and the reason for using threaded inserts for screw connections were explained. Then the paper shows the iterative process of working towards the final product by simulating the mounting bracket versions one after the other and improving them until the last one. After obtaining the shape of the final mounting bracket, a 3D printed model was produced, which is used for the production of sand molds. Using the software package Altair Inspire Cast, the casting of the Aluminium alloy into a mold was simulated and potential problems during the casting were indicated after which a live casting process was shown. At the end of the paper, the results of tests carried out during the production of the mounting brackets are shown so that real results could be compared to the ones obtained in the software packages
Determination of heavy metal content in cocoa samples using TXRF-W, TXRF-Mo and EDXRF techniques
No full textPlod stabla kakaovca jest zrno kakaa koje je ključni sastojak u proizvodnji kakao praha i čokolade. Zbog
velike zastupljenosti u ljudskoj prehrani, nužno je poznavanje sastava kakaa kako bi se osigurala kvaliteta i
sigurnost samih proizvoda. Glavni cilj ovog rada jest odrediti elementni sastav kakaa te usporediti rezultate
dobivene različitim analitičkim tehnikama (TXRF-W, TXRF-Mo, EDXRF). Uzorci su pripremljeni
mikrovalnom digestijom te u obliku peleta te je određeno prisustvo sljedećih elemenata: željezo, bakar,
cink, rubidij, stroncij, mangan, nikal i krom. Priprema uzorka u obliku peleta jeftinija je, manje zahtjevna i
ekološki prihvatljivija u odnosu na mikrovalnu digestiju. Analizom je utvrđeno da se rezultati dobiveni
različitim analitičkim tehnikama podudaraju (posebice između TXRF-Mo i EDXRF). Sve su se tehnike
pokazale kao vrlo korisne budući da omogućavaju identifikaciju i kvantifikaciju vrlo niskih koncentracija
elemenata prisutnih u uzorcima kakaa, s naglaskom na TXRF-Mo tehniku koja se pokazala kao
najosjetljivija.The fruit of the cocoa tree is the cocoa bean which is a key ingredient in the production of cocoa powder
and chocolate. Since cocoa is widely used in the human diet, it is necessary to know the composition of
cocoa in order to ensure quality and safety of the products themselves. The main goal of this work is to
determine the elemental composition of cocoa and to compare the results obtained by different analytical
techniques (TXRF-W, TXRF-Mo, EDXRF). The samples were prepared by microwave digestion and in the
form of pellets and the presence of the following elements was determined: iron, copper, zinc, rubidium,
strontium, manganese, nickel and chromium. Sample preparation in the form of pellets is less-expensive,
simpler and more environmentally friendly than microwave digestion. The analysis showed that the results
obtained with the different analytical techniques were consistent (especially between TXRF-Mo and
EDXRF). All techniques have proven to be very effective, as they allow the identification and
quantification of very low concentrations of the elements present in cocoa samples, with the TXRF-Mo
technique which proving to be the most sensitive
Quality control of Verbasci flos
No full textU okviru ovog diplomskog rada uspoređena su dva uzorka droge Verbasci flos sakupljena na dvije različite lokacije te je provedena kontrola kakvoće tih uzoraka. Određivanjem broj bubrenja i gubitka sušenjem ustanovljeno je da uzorci odgovaraju farmakopejskim zahtjevima, dok je u uzorku 2 pronađena nešto veća količina fragmenta čaške i ostalih stranih tvari. Mikroskopskim pregledom pronađeni su svi dijelovi koje Farmakopeja propisuje. Tankoslojnom kromatografijom (TLC) dokazana je prisutnost flavonoida i fenolnih kiselina koje su potom određene UV-Vis spektrofotometrijskom metodom te je sadržaj iznosio 0,053-0,075% i 0,08- 0,24%. Također određen je i sadržaj trjeslovina koji je iznosio 0,172-0,24%.As part of this thesis, two types of mullein flower from two different locations were compared and the quality control of these samples was carried out. By determining the swelling index and loss on drying, it was found that the samples correspond to pharmacopoeial requirements, while in the sample 2 there was slightly larger amount of fragments of the calyx, and other foreign substances was found. By microscopic examination we found all the parts prescribed by the Pharmacopoeia. Thin-layer chromatography (TLC) showed the presence of flavonoids and phenolic acids, which were then quantified by UV-vis spectrometric method, with the content ranging from 0.053% to 0.075% and 0.08% to 0.24%. The content of tannins was also determined, ranging from 0.172% to 0.24%
Macroelements in formulated dietary supplements for the treatment of inflammatory bowel diseases
No full textDodaci prehrani sadrže brojne minerale koji su vrlo važni za očuvanje fizioloških funkcija ljudskog organizma, a samim time i za očuvanje zdravlja. Kod bolesnika s upalnim bolestima crijeva dodatan unos minerala ublažava simptome uzrokovane deficitom minerala. Zbog toga je cilj ovog rada bio odrediti sadržaj makroelemenata (Na, K, Ca, Mg) u tržišno dostupnim dodacima prehrani za liječenje upalnih bolesti crijeva. Ispitivanje je provedeno plamenom tehnikom - atomskom apsorpcijskom spektrometrijom nakon postupka vlažnog spaljivanja mikrovalnom digestijom. Dobiveni rezultati su pokazali da je sadržaj analiziranih makroelemenata izrazito varijabilan. Kalij je bio najzastupljeniji mineral u ispitivanim uzorcima i imao je puno veću varijabilnost od kalcija, natrija i magnezija. Tvrde kapsule su sadržavale više koncentracije makroelemenata nego meke kapsule. I na kraju je važno za naglasiti kako se analiziranim dodacima prehrani primjenim u preporučenim i maksimalnim dozama unose manje količine od preporučenih za pojedini element, te tako nema opasnosti od njihove potencijalne toksičnosti.Dietary supplements contain numerous minerals that are very important for preserving the physiological functions of the human body and, thus for preserving health. In patients with inflammatory bowel diseases, additional intake of minerals alleviates symptoms caused by mineral deficiency. Therefore, this work aimed to determine the content of macroelements (Na, K, Ca, Mg) in commercially available dietary supplements for the treatment of inflammatory bowel diseases. The test was carried out using the flame technique - atomic absorption spectrometry after the process of wet burning with microwave digestion. The obtained results showed that the content of analyzed macroelements is highly variable. Potassium was the most abundant mineral in the tested samples and they have a much higher variability than calcium, sodium and magnesium. Hard capsules contain more concentration of macronutrients than soft capsules. Finally, it is important to emphasize that when used in recommended and maximum doses, the analyzed dietary supplements are taken in smaller amounts than recommended for each element, so there is no danger of their potential toxicity